Roller with surface friction

ABSTRACT

A roller is formed on an outer circumferential surface from inner to outer side with a coarsened layer and a finished layer. The coarsened layer is formed by way of subjecting the roller to coarsening, and the finished layer is formed by way of subjecting the roller to a predetermined surface finishing. A plurality of micro sharp points are formed on the finished layer to give the roller with high surface friction, so that the roller is suitable for push feeding sheet material.

FIELD OF THE INVENTION

The present invention relates to a roller with surface friction, andmore particularly to a roller having a coarsened layer and a finishedlayer formed on an outer circumferential surface thereof, and aplurality of micro sharp points formed on the finished layer to producehigh surface friction on the roller.

BACKGROUND OF THE INVENTION

A roller is an important element frequently used in different machinesto push feed sheet material. For example, a roller is frequently used ina printer, a photocopier, and many other office machines to roll on atop of a stack of sheet paper, so as to push and feed the sheet paper atthe highest position of the stack.

Most of the conventional rollers are produced to have a smooth outercircumferential surface that provides insufficient frictional force inpush feeding the sheet material and results in idling of the roller. Oneof the conventional ways to solve this problem is to form patterns onthe roller by engraving the outer circumferential surface of the roller.This solution is highly labor and time consuming, particularly for ametal roller.

Another conventional solution is to put a soft rubber sleeve over thecircumferential surface of the roller, in order to increase thefrictional force of the roller. However, the putting of the rubbersleeve over the roller increases not only the manufacturing cost butalso the manufacturing process of the roller. Moreover, the rubbersleeve has low thermal plasticity and durability, and tends to becomeworn out or hardened after being used over a prolonged time, preventingthe roller from stably push feeding the sheet material.

It is therefore tried by the inventor to develop a roller with surfacefriction to eliminate the drawbacks existed in the conventional rollers.

SUMMARY OF THE INVENTION

A primary object of the present invention is to provide a roller withsurface friction, so that the roller is suitable for push feeding sheetmaterial.

To achieve the above and other objects, the roller with surface frictionaccording to the present invention includes a coarsened layer and afinished layer formed on an outer circumferential surface of the rollerfrom inner to outer side. The coarsened layer is formed by way ofsubjecting the roller to coarsening, and the finished layer is formed byway of subjecting the roller to a predetermined surface finishing. And,a plurality of micro sharp points are formed on the finished layer togive the roller with high surface friction, so that the roller issuitable for push feeding sheet material.

BRIEF DESCRIPTION OF THE DRAWINGS

The structure and the technical means adopted by the present inventionto achieve the above and other objects can be best understood byreferring to the following detailed description of the preferredembodiments and the accompanying drawings, wherein

FIG. 1 is a fragmentary perspective view of a partially processed rollerof the present invention having a coarsened layer formed thereon;

FIG. 2 is a fragmentary perspective view showing the roller of FIG. 1has been further formed on the coarsened layer with a finished layer;and

FIG. 3 is a fragmentary perspective view of a fully processed roller ofthe present invention having a plurality of micro sharp points formed onthe finished layer thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Please refer to FIGS. 1 to 3, in which a roller 10 according to thepresent invention is shown. As shown, the roller 10 includes a coarsenedlayer 11 and a finished layer 12 sequentially formed on an outercircumferential surface of the roller 10 from inner to outer side. Thecoarsened layer 11 is formed by way of subjecting the outercircumferential surface of the roller 10 to coarsening. The finishedlayer 12 is formed on the coarsened layer 11 by way of subjecting thecoarsened layer 11 of the roller 10 to a predetermined surfacefinishing, such as metal plating, metal spraying, etc., so as to form ametal layer on the coarsened layer 11. As can be clearly seen from FIG.3, an outer circumferential surface of the finished layer 12 is providedwith a plurality of micro sharp points 13 to give the roller 10 a highsurface friction, enabling the roller 10 to effectively push feed sheetmaterial, such as sheets of paper.

The micro sharp points 13 are formed on the finished layer 12 by way ofetching, engraving, pressing or scooping, and have a size about 40μ to100μ each. The micro sharp points 13 so formed produce a gripping forceto grip a sheet material without the risk of piercing through the sheetmaterial, and therefore enable the roller 10 to serve as a rollersuitable for push feeding sheet material.

The present invention has been described with a preferred embodimentthereof and it is understood that many changes and modifications in thedescribed embodiment can be carried out without departing from the scopeand the spirit of the invention that is intended to be limited only bythe appended claims.

1. A roller with surface friction, comprising a roller having a coarsened layer and a finished layer formed on an outer circumferential surface of said roller from inner to outer side, and a plurality of micro sharp points formed on said finished layer; said coarsened layer being formed on the outer circumferential surface of said roller by subjecting the outer circumferential surface to coarsening; said finished layer being formed on an outer circumferential surface of said coarsened layer by subjecting said coarsened layer to a predetermined surface finishing; and said a plurality of micro sharp points formed on said finished layer providing said roller with high surface friction and thereby enabling said roller to effectively push feed sheet material.
 2. The roller with surface friction as claimed in claim 1, wherein said finished layer comprises a metal layer formed by metal plating.
 3. The roller with surface friction as claimed in claim 1, wherein said micro sharp points are formed on said finished layer by a method selected from the group consisting of etching, engraving, pressing, and scooping. 